Hello - all good information and thank you.
What I do not understand is why it is more present with the DG and not on the other vinyl. It would seem to me that if it is sound and vibration causing a feedback through the turntable system it would be noticeable regardless of the vinyl being played. The 45's seem to have a very wide dynamic range. I also do not hear it when I play the Ortofon test record. The disturbance has to start somewhere. I am going to further isolate the TT. TT now sits on a 20x15x1.25 wooden cutting board which is on top of a 60x17 buffet style wooden piece. I use some small felt rounds to level.